Method for Oligomerization of Ethylene and Reactor System therefor with Cooling Device

Abstract

The present invention relates to a method for oligomerisation of ethylene to form linear alpha-olefins in an oligomerisation reactor in the presence of solvent and catalyst, wherein a reaction product containing unreacted ethylene and light linear alpha-olefins is discharged from the oligomerisation reactor and passed to at least one first direct cooling device for separating the reaction product into an ethylene rich gaseous fraction and a light linear alpha-olefins rich liquid fraction, wherein at least a portion of the light linear alpha-olefins rich liquid fraction is passed to a second cooling device for lowering the temperature thereof and is subsequently re-introduced into the first direct cooling device; and to a reactor system therefore.

1 . A method for separating linear alpha-olefins formed by the oligomerization of an ethylene feed in the presence of a solvent and a catalyst, from a oligomerization reaction product containing unreacted ethylene and light linear alpha-olefins, comprising introducing the oligomerization reaction product into direct cooling device which separates the reaction product into an ethylene rich gaseous fraction and a light linear alpha-olefins rich liquid fraction, wherein that at least a portion of the light linear alpha-olefins rich liquid fraction obtained is passed to a second cooling device which reduces the temperature of the light linear alpha-olefins rich liquid faction and then re-introduced into the direct cooling device. 
   
   
       2 . The method according to  claim 1 , wherein re-introduction of the light linear alpha-olefins rich liquid fraction is at the top of the direct cooling device. 
   
   
       3 . The method according to  claim 2 , wherein unreacted ethylene is recycled into the ethylene feed. 
   
   
       4 . The method according to  claim 2 , wherein a portion of the light alpha-olefins rich liquid fraction is transferred to a separation device. 
   
   
       5 . The method according to  claim 4 , wherein the separation device is a rectification column. 
   
   
       6 . The method according to  claim 1 , wherein the direct cooling device contains random packing, structured packing and/or trays. 
   
   
       7 . The method according to  claim 1 , wherein the light alpha-olefins rich liquid fraction is re-introduced into the direct cooling device with added solvent. 
   
   
       8 . The method according to  claim 7 , wherein the added solvent comprises a heavier alpha-olefins fraction. 
   
   
       9 . The method according to  claim 8 , wherein light alpha-olefins rich liquid fraction comprises C 4 -C 8 -olefins and/or the heavier alpha-olefins fraction comprises C 10 -C 18 -olefins. 
   
   
       10 . The method according to  claim 9 , wherein the light alpha-olefins rich fraction is cooled in the second cooling device to a temperature of about 3° C. 
   
   
       11 . A reactor system for oligomerization of ethylene to form linear alpha-olefins, comprising an oligomerization reactor which produces a reaction product comprised of light linear alpha-olefins and unreacted ethylene, wherein the reaction product is introduced into a direct cooling device for a separation into a light linear alpha-olefins rich liquid fraction and an ethylene rich gas fraction according to  claim 1 . 
   
   
       12 . The method according to  claim 2 , wherein the direct cooling device contains random packing, structured packing and/or trays. 
   
   
       13 . The method according to  claim 6 , wherein the light alpha-olefins rich liquid fraction is re-introduced into the direct cooling device with added solvent. 
   
   
       14 . The method according to  claim 1 , wherein the light alpha-olefins rich fraction is cooled in the second cooling device to a temperature of about 3° C. 
   
   
       15 . The method according to  claim 6 , wherein the light alpha-olefins rich fraction is cooled in the second cooling device to a temperature of about 3° C. 
   
   
       16 . A reactor system for oligomerization of ethylene to form linear alpha-olefins, comprising an oligomerization reactor which produces a reaction product comprised of light linear alpha-olefins and unreacted ethylene, wherein the reaction product is introduced into a direct cooling device for a separation into a light linear alpha-olefins rich liquid fraction and an ethylene rich gas fraction according to  claim 6 . 
   
   
       17 . A reactor system for oligomerization of ethylene to form linear alpha-olefins, comprising an oligomerization reactor which produces a reaction product comprised of light linear alpha-olefins and unreacted ethylene, wherein the reaction product is introduced into a direct cooling device for a separation into a light linear alpha-olefins rich liquid fraction and an ethylene rich gas fraction according to  claim 8 .